Rheostat



v1,453,829 cs. w. CAMP May 1, 1 923.

RHEOS TAT Filed Jan. 10 1921 2 Sheets-Sheet 1 G. W. CAMP May 1, 1923.

RHEOSTAT 2 Sheets-Sheet 2 Filed Jan. 10 1921 wmfl 3- arm/140 Patented May 1, 192.3.

UNITED STATES PATENT OFFICE.

GEORGE WARREN CAMP, OE ZMOUNT VERNON, NETV YORK, ASSIGNOR TO HARD LEONARD ELECTRIC COIETANY, A CORPORATION OF NEW YORK.

RHEOSTAT.

Application filed January 10, 1921.

To all whom it may concern:

Be it known that I, GEORGE W. CAMP. a citizen of the United States, residing at Mount Vernon, in. the county of \Vestchester and State oi New York, have invented certain new and useful Improvements in Rheostats, of which the following is a. speci iication.

This invention relates to rheostats or regulators for controlling and adjusting the resistance in an electric circuit to any desired amount. The invention is particularly applicable to that general type of rheostats known as theatre dimmers, and to other uses where it is desired to independently control a number of different circuits.

It has been customary to employ a separate rheostat for each circuit controlled, the rheostat being in the form of a plate with an adjustable arm and to support a number of these rheostats side by side on a -frame with an independent handle for controlling each rheostat. Where the number of circuits to be controlled is comparatively large, this arrangement occupies considerable space, requiring one or more rheostats for each circuit. The space usually provided for this equipment is restricted and in any event, it is desirable to reduce the space required to as small an amount as possible.

The main object oi my invention is to economize the space occupied in the above type of rheostats and by means of my invention I can separately control two circuits by a combined rheostatic plate unit occupying the space formerly occupied by one rheostatic plate controlling one circuit. Another objectis to produce such a combined unit by a simple form of construction which may be conveniently assembled and manufactured. These and other objects and advantages will be understood from the following description and accompanying drawings, which illustrate one embodiment there- Fig. 1 is an elevation of one side of the vcombined unit. Fig. 2 is an elevation of the reverse side of the combined unit. Fig. 3 is a sectional view of a portion of the two plates showing the method of securing one within the other. i Fig. 4: is a detail showing partof the lever operating mechanism, and Fig. 5 is an edge view of the plate and operating levers.

Serial No. 436,024.

The rheostat illustrated forms a combined unit comprising two concentric circular rheostat plates, one located within the other. The outer portion of the combined unit includes the metal plate 1 having an upturned outer edge 1 and an upturned inner edge 1. Near the inner edge is a. series of circularly arranged fixed contacts 2 extending around the plate; and successively connected between them is the resistance con- (lllCiOlS 3. The resistance conductors ex tend outwardly from the fixed contacts toward the outside rim of the plate as shown in Fig. 1. The resistance conductors and contacts are insulated from the metal plate by an intervening layer of insulating. material; and the base portion of the contacts and the resistance conductors are insulated and protected by a coating of insulating material, preferably an adhesive vitreous enamel.

The inner plate in this instance includes an inner plate having an outer upturned edge et On this plate are two rows of circularly arranged fixed contacts From the outer row the resistance conductors 6 extend outwardly and from the inner row resistance conductors 8 extend inwardly. These contacts and resistance conductors are fixed in position and insulated from, the metal plate and are coated with an insulating protective enamel. the same as the contacts and resistance conductors on the re verse side or the outer plate.

The inner plate is secured within the outer plate by bolts. nuts and washers 7, which pass through cut-away portions in the adjacent rims of the two plates as shown in Fig. 3. Each of the two plates have circular heat radiating rims or flanges 8 on the reverse side from that carrying the fixed contacts.

The inner plate has a central hub through which extends the shaft 9 which is fixed thereto. This fixed shaft carries thereon a rotatable sleeve 10 having integral therewith a disk 10 On the inner side of this disk and lined thereto is the contact arm 11. The inner taco of the contact arm carries a conducting strip 11, the outer end of which has a contact engagement with the fixed contacts 2, and the inner end of which has a contact engagement with. a conducting ring 12 fixed to the inner plate 4, but insulated therefrom. Fixed to the rim 1, but insulated therefrom, are the four terminals 13. From one terminal 13 a. conductor 13 extends to and is electrically connected with the conducting ring 12. Another terminal 13 is electrically connected by a conductor 13 to the first fixed contact 2. Evidently movement of the contact arm in a counterclockwise direction from the position shown in Fig. 1, will gradually increase the amount of the resistance conductors 3 in a circuit connected to the two right-hand terminals 13 of Fig. 1. The contact arm is movable nearly 360, the stop 1 1 limiting the movement in the resistance-all-out position and in the resistance-all-in position.

The contact arm is rotated in either direction as desired by means of the hand lever 15, the lower {end of which is pivotally mounted on a suitable support. A rod 16 is p'ivotally connected to the handle and has secured to its inner end the bow or bracket 17. A chain 18 is secured at its ends to the projecting portions of the bracket 17, the chain having a turn around the sleeve 10, one of the links of the chain having a projecting pin 18" engaging a hole in the sleeve 10, as shown in Fig. 1. Evidently movement of the bow or bracket 17 in either di rection by movement of the handle 15, will cause the sleeve 1.0 and the contact arm 11 to be correspondingly moved in either di-- rection as desired.

On the reverse side of the unit is the con-- tact mechanism for adjusting the resistance of the inner plate. In this instance a conductor 13 extends from one terminal 13 through an opening in the inner plate and is connected to the first contact of the outer row 5, at the left of the stop 1 1. Another conductor 13 extends from the remaining terminal 13 to an insulated terminal 19 which extends through the inner plate. At the opposite side of the plate a conductor 13 is connected to the terminal 19 and to the first contact of the inner row of fixed contacts 5, at the right of terminal 19 as viewed in Fig. 2.

On the side of the combined unit shown in Fig. 2, the shaft 9 carries another sleeve 20, which is rotatable on the shaft 9 and has an integral flange or disk A contact arm 21 is fixed to the inner face of the flange 20 One end of the contact arm extends to and has contact engagement with the outer row of fixed contacts while the opposite end of the contact arm extends to and has contact engagement with the inner row of contacts 5. It is evident that in the position shown in Fig. 2, the contact arm makes a direct connection between the contacts to which the conductors 13 and 13 are connected, and consequently no resistance is included in the circuit. Rotation of the cow tact arm in a clockwise direction gradually inserts resistance until the maximum resistance is included by a movement of nearly 360 to the resistanceall-in-position.

The contact arm is operated in the same manner as already described with reference to the contact arm on the other side of the plate, there being a pivoted hand lever 15 having pivotally connected thereto the rod 16 to which is also connected a bracket or bow 17. The bow 17 carries the chain 18 which latter engages the sleeve 20, in the same manner as described with reference to the chain 18 engaging the sleeve 10.

The two plates are evidently readily detachable, one from the other, and easily assembled. In the process of manufacture, the insulating coatings can best be applied with the plates horizontal and the side on which the conductors are located, or to be located, uppermost. W'ith my improved invention in this process, the plates may have the insulating coatings and resistance conductors and fixed contacts applied with the plates detached, or they may be united by the attaching means shown with resistance carrying sides uppermost. After enameling they may be detached and one plate reversed with reference to the other and reassembled, after which the movable parts are added and the auxiliary connections are made. My invention thus gives a convenient method of manufacture and assembly.

It is evident that by my invention the space occupied by the combined rheostatic plate. is no more than that previously occupied by one rheostatic plate and that independent control of two circuits is obtainable. Also by placing the operating mechanism on opposite sides of the unit, the handles are suitably spaced from each other and the amount of axial space required for the two operating mechanisms is also a minimum, and no greater than that required for the suitable and necessary spacing of the operating handles. Additional units may be added for the control of additional circuits and supported on the four parallel bars 22 by means of bolts 23, which engage the slotted ears 1" formed on the rim of the plate 2; or the units may be otherwise suitably supportedv in groups up to the number required for any particular installation.

My invention is capable of embodiment in various modifications other than the particular form shown, without departing from the scope thereof.

I claim l. A rheostat comprising a plate, resistance conductors and fixed contacts on one side of said plate, resistance conductors and fixed contacts on the reverse side of said plate within the other set of resistanceconductors and fixed contacts, heat radiating flanges on both sides of said plate and located opposite said resistance conductors tively, and controlling means on each side of said plate.

2. A rheostat comprising a plate, resistance conductors and fixed contacts on one side of said plate, resistance conductors and fixed contacts 011 the reverse side of said plate Within the other set of resistance conductors and fixed contacts, heat radiating flanges on both sides of said plate, and located opposite said resistance conductors respectively, and controlling means on each side of said plate, said controlling means being independently separable.

3. A rheostat comprising a plate having a central portion and an outer portion, one within the other, resistance conductors and fixed contacts on one of said portions, resistance conductors and fixed contacts on the other of said portions, and controlling means for each of said portions.

4-. A rheostat comprising a plate having an inner central portion and an outer portion, resistance conductors and fixed contacts on one side of one of said portions, resistance conductors and fixed contacts on the opposite side of the other of said portions, and controlling means on opposite sides of said plate for each of said portions.

A rheostat comprising a plate having a central portion and an outer portion, said portions being detachable one from the other, resistance conductors and fixed contacts on each of said portions respectively, and controlling means for each of said portions.

6. A rheostat comprising a plate having a central portion and an outer portion, said portions being detachable one from the other, resistance conductors and fixed contacts on one of said portions, resistance conductors and fixed contacts on the other of said portions on the opposite side thereof, and controlling means for each of said portions on the opposite sides of said plate.

7. A rheostat comprising a plate having a central portion and an outer portion located in the same plane, resistance conductors and fixed contacts on each of said portions respectively, and independently operable controlling means for each of said portions.

8. A rheostat comprising a plate having a central portion and an outer portion located in the same plane, resistance conductors and fixed contacts on one of said portions on one side of said plate, resistance and fixed contacts on the other of said portions on the opposite side of said plate, and controlling means on each side of said plate.

9. A rheostat comprising a plate having a central portion and an outer portion located in the same plane, resistance conductors and fixed contacts on one of said portions on one side of said plate, resistance conductors and fixed contacts on the other of said portions on the opposite side of said plate, and controlling means on each side of said plate, said controlling means being independently operable.

GEORGE WARREN CAMP. 

